Patent Literature 1 discloses a damping force adjustable hydraulic shock absorber of the type having a control valve mounted alongside and including a partition member (baffle plate). In the shock absorber, the partition member is manufactured by vulcanization-bonding a rubber partition, which is an elastic seal member, to a metallic plate part. In this regard, however, there is a demand that the baffle plate be further improved in productivity and assembleability.